JP2928602B2 - Circuit breaker for wiring - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a circuit breaker for tripping a circuit when an overcurrent flows to cut off the circuit, and in particular, releases the engagement with a trip member. The present invention relates to an improvement in a mounting structure of an interlocking shaft and a fixed frame that supports the interlocking shaft.

[Conventional technology]

As a prior art of a circuit breaker for wiring, Japanese Utility Model Application Laid-Open No. 61-107135
Japanese Patent Application Publication No. 1-55737, Japanese Utility Model Application Publication No. 59-178855, and the like.

Japanese Unexamined Utility Model Publication No. Sho 61-107135 (first prior art) discloses a substantially U-shaped fixed frame a having two side walls b and b 'as shown in FIGS. 11 (a) and 11 (b). An arm c is formed on one of the side walls b toward the other side wall b 'by bending, a stopper step d is formed on the arm c, and an arm formed at the tip of the stopper step d. Stop part e,
It is fitted into the engagement hole f formed in the other side wall b ',
The b and b 'are opposed to each other with uniform dimensions from the bent base to the open end of the fixed frame a and are connected to each other.

Japanese Patent Publication No. 1-55737 (second prior art) forms a bent portion on one side wall of a fixed frame toward the other side wall, and provides a bent portion at an end portion on the other side wall. Protrusions that fit into the recesses formed are formed, and the projections and the recesses are fitted and caulked and fixed, thereby increasing the strength and the like of the fixed frame.

Japanese Utility Model Publication No. 59-178855 (third prior art) discloses an improvement in the structure of a fixed frame and an interlocking shaft attached to the fixed frame. An opening groove is formed on the side of the interlocking shaft, while a small-diameter shaft portion and a cylindrical shaft portion are formed on the side of the interlocking shaft. By inserting the small-diameter shaft portion and supporting the cylindrical shaft portion in a circular hole, the interlocking shaft is rotatably supported on the fixed frame, whereby the turning range of the interlocking shaft can be widened. The rotation of the interlocking shaft can be smoothly performed.

[Problems to be solved by the invention]

By the way, the following points are not considered in the above-described conventional technology.

That is, in the first prior art, since both sides b and b 'of the fixed frame a are connected by the arm c,
The variation in the interval between b and b 'is small and stable, but the arm c
Space is required. For this reason, since many components besides the interlocking shaft are operated inside the fixed frame, it is difficult to secure a space for the arm c so as not to hinder the operation, and design restrictions are imposed. Problem.

In the second prior art, since the portion supporting the interlocking shaft in the fixed frame is located at a position separated from the bent portion, the interval between both side walls supporting the interlocking shaft of the fixed frame tends to vary. Therefore, the operation of the circuit opening / closing mechanism operating in the fixed frame causes the support portion of the interlocking shaft in the fixed frame to fall inward, so that the movement of the interlocking shaft is disturbed, and there is a problem that the operating characteristics vary.

The third prior art is provided with a small-diameter shaft portion and a cylindrical shaft portion on the interlocking shaft to attach the interlocking shaft to the fixed frame, and when forming this interlocking shaft, it is not disclosed,
A shaft having a small diameter shaft portion and a cylindrical shaft portion is formed in advance,
It is conceivable that the shaft is set in a mold for an interlocking shaft and then molded by injecting a resin. However, in this case, not only does the number of man-hours for manufacturing the shaft increase, but also the shaft is put into a mold and integrally formed, so that the mold structure becomes more complicated and the cost is increased.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, it is an object of the present invention to prevent a side wall of a fixed frame from falling inward, to smoothly rotate an interlocking shaft, and to easily manufacture an interlocking shaft. To provide equipment.

[Means for solving the problem]

In order to achieve the above object, in the present invention, one of the both side walls of the fixed frame and the rotation center of the interlocking shaft, or separately from the both side walls and the interlocking shaft, is disposed on the rotation center axis of the interlocking shaft. The rotation support shaft is formed so that the distance between both side walls is kept constant by the rotation support shaft.

[Action]

In the present invention, as described above, the rotation support shaft disposed on the rotation center axis of the interlocking shaft is configured to keep the distance between both side walls constant, so that the both side walls of the fixed frame fall inside each other. Can be prevented. Therefore, compared with the first conventional technique, there is no need to consider the problems caused by the use of the arms, that is, to secure the space and restrict the design, and the like. Are arranged on the rotation center axis of the interlocking shaft, so that the distance between both side walls does not vary. Therefore, the rotation of the interlocking shaft can be made smooth.

Further, as described above, if the rotation support shaft is formed separately from the interlocking shaft, it is not necessary to provide a special shape for the rotation support shaft, and the interlocking shaft can be simplified as compared with the third related art, The mold structure of the interlocking shaft does not become complicated.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory diagram of an ON state showing a first embodiment of a circuit breaker according to the present invention, and FIGS. 2 and 3 are partially cutaway perspective views showing an assembly of a fixed frame and an interlocking shaft. FIG. 4 is an explanatory view when the fixed frame and the interlocking shaft are assembled.

In the circuit breaker of the embodiment, as shown in FIG. 1, a casing is constituted by a base 1 and a cover 2 provided thereon, and a circuit opening / closing mechanism is provided in the casing.

In the circuit opening / closing mechanism, a fixed contact 3 is fixed to a base 1, and a movable contact 4 having a contact 4 a capable of contacting a contact 3 a of the fixed contact 3 is attached to a movable frame 5. The movable frame 5 is held in a casing B composed of the base 1 and the cover 2, supports the movable contact 4 by a shaft 6, and replaces the contact 4 a of the movable contact 4 with the contact 3 a of the fixed contact 3. , A constant contact pressure is applied by the force of the spring 7.

The movable frame 5 has a lower portion of the lower lever 8, an upper portion of the lower lever 8 is connected to a lower portion of the upper lever 9 by a pin (not shown), and an upper portion of the upper lever 9 is connected to a hook 11 by a shaft 10. Are linked. Hook 11 is hook axis
By 12, it is rotatably attached to the fixed frame 30 and is engaged with the trip member 32.

The fixed frame 30 has a substantially U-shape and is fixed to the base 1. The trip frame 32 is supported by pins 33, and an interlocking shaft 31 described later is also supported. Trip material
32 engages with the hook 11 and also engages with the interlocking shaft 31. The number of the interlocking shafts 31 corresponding to the number of each phase of the wiring breaker is integrally formed along the axial direction,
Also, the bimetal 21 is rotatably mounted on the fixed frame 30 and, when engaged with the trip member 32, when an overcurrent flows and the bimetal 21 hits, the trip member 32 is pressed by the pressing force.
Is disengaged.

On the other hand, a handle 13 protruding to the outside from an opening formed in the upper portion of the cover 2 and a handle lever 14 integrally attached thereto are rotatably held by a handle shaft 15, and the handle lever 14 and A drive spring 16 is stretched between the pins.

A lead wire is provided at the end of the movable contact 4 opposite to the contact 4a.
A heater 18 is connected via a heater 17, and a terminal block 20 is connected to the heater 18 via a conductor 19. A bimetal 21 constituting a part of a tripping mechanism is attached to the heater 18, and when an overcurrent flows in the circuit, the heat causes the bimetal 21 to bend to the left in FIG. 1 to rotate the interlocking shaft 32. Like that.

The tripping mechanism has a movable core 22 that is attracted to the conductor 19 by the electromagnetic force of the conductor 19 when a large-capacity overcurrent flows, in addition to the bimetal 21. The movable core 22 is a mounting frame 23
The interlocking shaft 31 is rotated so that the engagement between the interlocking shaft 31 and the trip member 32 is released by being sucked by the conductor 19 below.

Further, a fixed contact 3 and a movable contact 4 are provided in the cover 2.
An arc extinguishing device 24 for extinguishing an arc generated during the arc is provided.

In FIG. 1, when the movable contact 4 comes into contact with the fixed contact 3 and the circuit is turned on in FIG. 1, when the handle 13 is rotated clockwise about the handle shaft 15, Similarly to the handle 13, the handle lever 14 also rotates.
Rotates counterclockwise around the axis 10 and raises the lower lever 8 upward, and the upward movement of the lower lever 8 causes the movable frame 5 to rotate clockwise around the axis 6 and the movable contact 4 By turning in the same direction, the contact 4a of the movable contact 4 separates from the contact 3a of the fixed contact 3 and is turned off. When the handle 13 is turned counterclockwise in the off state, the handle lever 14 also rotates,
The upper lever 9 rotates clockwise about the shaft 10 by the spring force of the drive spring 16 and pushes down the lower lever 8 to move the movable frame 5 by moving the lower lever 8 downward.
Rotates counterclockwise about the axis 6 and the movable contact 4
Also rotates in the same direction so that the contact 4a is fixed contact 3
, And the circuit is turned on.

Also, if an overcurrent flows in the ON state, the bimetal 21 bends due to the heat of the conductor 19 and the interlocking shaft 31 is rotated counterclockwise, or the movable core 22 is attracted to the conductor 19 to interlock. When the shaft 31 is rotated in the same direction, the engagement between the interlocking shaft 31 and the trip member 32 is released, and the trip member 32 rotates clockwise about the pin 33 by the pressing force of the interlocking shaft 31, and Trip member 32 and hook 11
The hook 11 rotates counterclockwise around the shaft 10 by the spring force of the drive spring 16, and the upper lever 9 and the lower lever 8 move upward to move the movable frame 5.
Is rotated clockwise, the movable contact 4 separates from the fixed contact 3 and trips to cut off the circuit.

The bimetal 21 of the tripping mechanism is used in a number corresponding to each phase. When an overcurrent flows in a circuit of an arbitrary phase, the interlocking shaft 31 is operated by the bimetal 21 on the circuit side.

In the circuit breaker of the embodiment, the interval between the side walls 30a, 30a of the fixed frame 30 is kept constant by the rotation support shaft 35, and the interlocking shaft 31 is fixed by the rotation support shaft 35. 30 is rotatably supported.

That is, as shown in FIGS. 2 to 4, the rotation support shaft 35 is made of a material having appropriate strength, has a length slightly longer than the interval between the side walls 30a, 30a, and is uniform in the axial direction. Is formed. The fixed frame 30 is disposed between the guides 1a, 1a formed upright on the base 1 as shown in FIG.

Also, the rotation support shaft 31 '
An insertion hole 36 for inserting the 35 is formed. For example, in the case of a three-phase wiring breaker, the insertion hole 36 is formed so that the rotation center part 31 ′ located in the central phase thereof has both side walls 30 a, 30 a of the fixed frame 30.
The rotation support shaft 35 is formed along the axial direction so that the rotation support shaft 35 can pass through the rotation center portion 31 '. The central phase portion of the interlocking shaft 31 is formed larger than the other phase portions so that engagement with the trip member 34 and release thereof can be performed.

On the other hand, recesses 30b, 30b are fitted inside the side walls 30a, 30a of the fixed frame 30 to fit and support the ends of the rotation support shaft 35.
30b is formed. The recesses 30b, 30b are formed on both side walls 30a, 30a.
Are formed by punching outwardly facing portions of the rotating support shaft 35, and the interval between them is substantially the same as the length of the rotary support shaft 35.

At the time of assembling the interlocking shaft 31 to the fixed frame 30, as shown in FIG. 4, the insertion hole 37 provided in the next phase with the insertion hole of the interlocking shaft 31 is previously passed as shown by an arrow a. Then, the side walls 30a, 30a are spread out as shown by the broken lines, and the end portions of the rotary support shaft 35 are respectively inserted into the concave portions 30b, 30b of the side walls 30a, 30a in this state. Therefore, an insertion hole 37 is formed in the adjacent phase of the interlocking shaft 31 so that the rotation support shaft 35 can pass through the insertion hole 36. The fixed frame 30 has a side wall 30a.
Is formed of, for example, a metal plate so that it can be returned to the original position by the elastic force of the side wall 30a even if it is spread.

In the wiring breaker of the embodiment, as described above, the rotation center portion 31 ′ of the interlocking shaft 31 is attached by the rotation support shaft 35 between the concave portions 30 b and 30 b formed on both side walls 30 a and 30 a of the fixed frame,
The rotation support shaft 35 is connected to the interlocking shaft 31 between the side walls 30a, 30a.
Is disposed on the rotation center axis by passing through the rotation center portion 31 ′, the side walls 30 a, 30 a can be prevented from falling down inside by the rotation support shaft 35 and the insertion hole 36. Therefore, compared with the first conventional technique, the side wall 30a can be reinforced without providing the arm c, so that it is not necessary to consider the problem caused by using the arm c, that is, to secure a space or restrict the design. Become.

Also, as compared with the second prior art, since the rotation support shaft 35 is disposed on the rotation center axis between the side walls 30a, 30a, the distance between the side walls 30a, 30a does not vary, and therefore the interlocking shaft The rotation of 31 can be smooth. In addition to this, the rigidity of the insertion hole 36 can be increased by the rotation support shaft 35,
In addition, the rotation support shaft 35 and the concave portion 30b are in surface contact with each other, and the rotation support shaft 35 and the interlocking shaft 31 are also in surface contact.

Furthermore, as described above, if the rotation support shaft 35 is formed separately from the interlocking shaft 31, it is not necessary to provide a special shape on the outer periphery of the rotation support shaft 35. Can be simplified, and the mold structure of the interlocking shaft 31 does not become complicated.

 FIG. 5 shows a second embodiment of the present invention.

In the figure, convex portions 30c, 30c are formed inside the side walls 30a, 30a of the fixed frame 30 to hold the rotation support shaft 45. The rotation support shaft 45 is formed to have approximately the same size as the space between the two convex portions 30c, 30c, and the insertion hole of the 31 '
It is shorter than 36. And the three insertion holes 36 of the interlocking shaft 31
Insert the projections 30c, 30c of the fixed frame 30 at both ends of the
By contacting both end surfaces of the rotation support shaft 45 included in 6 with the convex portions 30c, the side walls 30a, 30a are prevented from falling inward.

According to this embodiment, there are basically the same effects as in the first embodiment, and also the following effects. That is, since the convex portion 30c having the same diameter as the rotation support shaft 45 is formed inside the side wall 30a, it does not protrude outside the side wall 30a, and the convex portion 30c has a bag-like shape as in the first embodiment. Unlike the concave portion 30b, the fixed frame 30 can be downsized.

 FIG. 6 shows a third embodiment of the present invention.

In this case, the fixed frame 30 is formed of a material that cannot provide unevenness on the side wall 30a.

That is, at both ends of the rotation support shaft 55, extension shaft portions 55a having a diameter smaller than the diameter are formed along the axial direction, respectively.
Holes 30d for inserting the respective extension shaft portions 55a are provided in both side walls 30a, 30a. And the rotation support shaft 55 passing through the interlocking shaft 31
The extension shaft portion 55a is inserted into the hole 30d, thereby assembling.

 FIG. 7 shows a fourth embodiment of the present invention.

In the figure, convex portions 3 protruding outward on both side walls 30a, 30a.
0e are respectively formed, and concave portions 31a matching the convex portions 30e are formed in the connecting portions 30b, 30b of the interlocking shaft 31, respectively. Further, extension shaft portions 65a are formed at both ends of the rotation support shaft 65, and concave portions 30f that match the extension shaft portions 65a are formed in the side walls 30a. Therefore, both side walls by the rotation support shaft 65
In addition to maintaining the interval between 30a, 30a, the interlocking shaft 31 is rotated by the concave portion 31a and the convex portion 30e. According to this embodiment, not only is it unnecessary to insert the rotation support shaft 65 into the interlocking shaft 31, but also it is not necessary to form an insertion hole for inserting the rotation support shaft 65, so that the cost of the interlocking shaft 31 can be reduced. It is possible to simplify the assembly.

 FIG. 8 shows a fifth embodiment of the present invention.

In the figure, the extension shaft portions 75a are respectively formed at both ends of the rotation support shaft 75, while the extension shaft portions 75a are formed on both side walls 30a, 30a.
Is formed, and a concave portion 31c that is compatible with the extension shaft portion 75a is formed in the connection portion 31b of the interlocking shaft 31, and the extension shaft portion 75a of the rotation support shaft 75 passes through the side wall 30a. Recess
I try to get into 31c. Therefore, according to this embodiment, the same effects as in the fourth embodiment can be obtained.

 FIG. 9 shows a sixth embodiment of the present invention.

In this case, the second embodiment is applied. That is, the convex portions 30a that fit into the insertion holes 36 of the interlocking shaft 31 are respectively formed on the both side walls 30a, 30a, and the convex portions 30g fit into the insertion holes 36, so that the distance between the both side walls 30a, 30a is made constant. While maintaining, the interlocking shaft 31 is rotatably supported, and also has the function of a rotation support shaft. For this reason, the width of the rotation center portion 31 'of the interlocking shaft 31 is substantially the same as the width between the side walls 30a, 30a.

Therefore, according to this embodiment, the side wall of the fixed frame 30
Since the projection 30g provided on 30a functions as a rotation support shaft,
It is not necessary to use the rotation support shaft used in the embodiments described above, and the number of parts can be reduced accordingly. Further, the interlocking shaft 31 can be simplified, and the mold structure of the interlocking shaft 31 does not become complicated.

As another example of such an embodiment, as shown in FIG. 10, an extension shaft portion 31d is provided on the end face of the rotation center portion 31 'of the interlocking shaft 31.
The same effect can be obtained even if holes are provided in both side walls 30a so as to be compatible with the extension shaft portions 31d, and the rotation center portion 31 'functions as a rotation support shaft.

In each of the embodiments, an example in which the present invention is applied to a three-phase type circuit breaker is shown. However, in the present invention, the present invention can be applied not only to the number of phases larger than that but also to the single-phase type. .

〔The invention's effect〕

As described above, according to the present invention, the width between both side walls of the fixed frame is kept constant by the rotation support shaft arranged on the rotation center axis of the interlocking shaft, and the both side walls of the fixed frame fall inside each other. It is not necessary to consider the securing of space and design restrictions, etc., and the spacing between both side walls does not vary, resulting in smooth rotation of the interlocking shaft. This has the effect of increasing reliability.

In addition, if the rotation support shaft is formed on one of the fixed frame and the interlocking shaft, or separately from the fixed frame and the interlocking shaft, it is not necessary to provide a special shape for the rotation support shaft. As a result, the mold structure of the interlocking shaft is not complicated, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an ON state showing a first embodiment of a circuit breaker according to the present invention, and FIGS. 2 and 3 are partially broken perspective views showing assembling of a fixed frame and an interlocking shaft. FIG. 4 is an explanatory view of assembling a fixed frame and an interlocking shaft, FIG. 5 is an explanatory view of a main part showing a second embodiment of the present invention, and FIG. FIG. 7 is an explanatory view of a main part showing a third embodiment of the present invention, FIG. 7 is an explanatory view of a main part showing a fourth embodiment of the present invention, and FIG. 8 is a fifth embodiment of the present invention. FIG. 9 is an explanatory view of a main part showing a sixth embodiment of the present invention, FIG. 10 is an explanatory view of a main part showing another embodiment of the present invention, and FIG. 1) and 1 (b) are an overall perspective view of a fixed frame and an enlarged perspective view of a main part showing a first related art. 30: fixed frame, 30a: side wall, 30b: concave, 30c: convex, 30d: hole, 30e: convex, 30f: concave, 31: interlocking shaft, 3
1 ′… Center of rotation, 31c, 31d… Extended shaft of interlocking shaft, 35,45,
55, 65, 75: rotary support shaft; 55a, 65a, 75a: extension shaft portion of rotary support shaft, 36: insertion hole.

Claims (1)

(57) [Claims] A circuit breaker for rotatably supporting an interlocking shaft of a circuit opening / closing mechanism on a substantially U-shaped fixed frame and turning off the interlocking shaft when an overcurrent flows through the circuit. In any one of the two side walls of the fixed frame and the rotation center portion of the interlocking shaft, or separately from the both side walls and the interlocking shaft, a rotation support shaft arranged on the rotation center axis of the interlocking shaft is formed. ,
A circuit breaker for wiring, wherein the rotation support shaft is used to keep a constant distance between both side walls.